/*
 * Copyright (c) 2014 pkzd/1.0, 颜文泽(robin)
 * All rights reserved.
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *     1 Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     2 Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include	<param.h>

.text
.globl end, start
start:
	movl	$end, %ebx
	lea	1*PAGESIZ(%ebx), %esp	
	movl	%esp, tss + 0x4 
	movl	$KERN_DSEL, tss + 0x8
	lea	1*PAGESIZ(%ebx), %edi
	movl	$(PG_W| PG_P|PG_PS), %eax
	movl	%eax, (%edi)	
	movl	$tss, %eax
	sal	$0x10, %eax
	orl	$0x67, %eax		
	movl	$gdt, %edi
	movl	%eax, 0x28(%edi)
	lgdt	gdtr
	movl	$TSS_SEL, %eax
	ltr	%ax
	movl	%cr4, %eax
	orl	$CR4_PSE, %eax
	movl	%eax, %cr4
	lea	1*PAGESIZ(%ebx), %eax
	movl	%eax, %cr3	
	movl	%cr0, %eax
	orl	$(CR0_PG|CR0_WP), %eax
	movl	%eax, %cr0
	call	main
spin:
	jmp	spin
.data
.align 32
gdt:
        .word   0x0000, 0x0000, 0x0000 ,0x0000
        .word   0xffff, 0x0000, 0x9a00, 0x00cf
        .word   0xffff, 0x0000, 0x9200, 0x00cf
        .word   0xffff, 0x0000, 0xfa00, 0x00cf
        .word   0xffff, 0x0000, 0xf200, 0x00cf
        .word   0x0000, 0x0000, 0x8910, 0x0000
gdtr:
        .word (. - gdt -1)
        .long   gdt
.globl tss
tss:
        .space  0x68
